WASHINGTON, D.C.--In what could be a prelude to warmer scientific relations between the United States and Iran, a delegation of five high-ranking Iranian scientists left today after 5 days of meetings here with several nongovernmental scientific organizations. It was the first visit of its kind since the 1979 Islamic revolution that toppled the shah.

The trip was arranged by Jeremy Stone, president of the Federation of American Scientists, who led a three-person FAS delegation to Iran last December. He says it took 8 months of "tortuous negotiations" with the Iranian bureaucracy to arrange a visit for his hosts, who were eager to discuss possible collaboration with their U.S. counterparts in fields such as renewable energy, environmental cleanup, earthquake hazard mitigation, agriculture, education, and health. "We are interested in exchanges by students and faculty members and in joint research," says Ali Mansoori, a chemical engineering professor at the University of Illinois, Chicago, and a foreign member of the Iranian Academy of Sciences, who served as the group's liaison.

The meetings were mostly show-and-tell exercises for groups such as the American Physical Society (APS), the American Chemical Society, and the American Association for the Advancement of Science (publisher of Science). "There have been no ties for a long time," says Abolhassan Vafai, president of Iran's civil engineering society and founding editor of the fledgling journal, Scientia Iranica. "So any contact would be welcome." The U.S. National Academy of Sciences, the U.S. National Academy of Engineering, and the Institute of Medicine, which co-hosted the trip, are hoping to send a delegation to Iran next spring to flesh out some of the ideas raised during a daylong meeting last Thursday.

A major obstacle to closer links, however, is restrictions on travel. Because there is no U.S. consulate in Iran, Iranians must go to a third country to submit a visa application, then make a second trip, often several months later, to pick up the visa if it has been approved. Full diplomatic relations would be a boon to increased cooperation, says the APS's Irving Lerch, who noted that both Iranian President Khatami and President Clinton have expressed a desire for closer cultural ties between the two countries.